The line-of-sight (LOS) scanning patterns of the automatically controlled radars or optical sensors implemented in pods, aircraft or ground vehicles are conventionally patterns of the following types:                sideways scan at constant angle, also called strip-map mode in the radar field;        spotlight on a fixed point (=used to track a fixed point);        tracking of a moving target;        circular scan, for ground applications.        
The first type of scan allows a band of terrain to be scanned, but with a constant view point between the aircraft and the point on the ground that is scanned.
The second allows an object on the ground to be seen from various view points but covers a very limited zone of the ground.
The third is a variant of the second, and does not guarantee a multiplicity of view points.
The fourth is similar to the first and has a constant azimuth angle.
These four classes of scan do not allow, with a good angular resolution, a large extent of ground to be viewed from various viewpoints.